1. Field of the Invention
The present invention relates to a photocoagulation apparatus for photocoagulating an affected part (a treatment part) by irradiating the part with a treatment laser beam.
2. Description of Related Art
Conventionally, there has been known a photocoagulation apparatus for photocoagulating an affected part of a patient by irradiating the part with a treatment laser beam while allowing an operator to observe the affected part through an observation optical system such as a slit-lamp and others. In particular, an ophthalmic photocoagulation apparatus is arranged to utilize the thermal effect of laser to produce protein coagulation in the tissue of the fundus of a patient""s eye. This apparatus is used for treatment for a macular functional disorder and a visual functional high disorder. A white spot which is generated from the protein coagulation is called a coagulation spot. The operator would empirically adjust laser irradiation conditions such as power, time, etc. of the treatment laser beam to be irradiated, while observing a forming state (progress) of the coagulation spot.
On the other hand, in an operation for quasi panretinal photocoagulation (quasi-PRP), for example, plural coagulation pots each having a substantial uniform diameter of 500-600 xcexcm have to be produced over the affected part. FIG. 7 shows a schematic image of an eye fundus with a number of coagulation spots produced.
In this case, it is necessary that the coagulation spots are produced at various sites in the affected part as shown in FIG. 7. However, coagulating conditions and states depend on the light-absorbing property of the tissue at each site in the affected part. Even if the operator adjusts the irradiation conditions (power, time, etc. of laser irradiation) of the treatment laser beam, a coagulation spot could not always be formed as intended in each irradiation site.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide a photocoagulation apparatus which is simply operable by an operator to produce coagulation spots each being uniform in color and spot size in an affected part irrespective of light-absorbing property of the tissue of the affected part.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the purpose of the invention, there is provided a photocoagulation apparatus for coagulating an affected part of a patient by irradiating the part with a treatment laser beam emitted from a laser oscillator, including: input means for setting an irradiation condition of the treatment laser beam; detection means for optically detecting a coagulating state of a coagulation part produced by irradiation of the treatment laser beam; analysis means for analyzing the coagulating state detected by the detection means as compared with a desired coagulating state to be produced by irradiation of the treatment laser beam under the irradiation condition set with the input means; and control means for instructing a change in the irradiation condition as needed based on a result of analysis by the analysis means.
According to another aspect of the present invention, there is provided a photocoagulation apparatus for coagulating an affected part of a patient by irradiating the part with a treatment laser beam, the apparatus including: an input section provided with keys for setting an irradiation condition including at least either irradiation power or irradiation time of the treatment laser beam; an irradiation optical system including a laser oscillator which emits the treatment laser beam, for delivering the treatment laser beam emitted from the laser oscillator to the affected part to irradiate the part; a photographing optical system including a photoelectric image pick-up device for photographing an area including the affected part; video image processing means for processing an image of the area photographed by the photographing optical system to take image data of a coagulation spot produced by irradiation of the treatment laser beam from the image data of the photographed area, the video image processing means being connected with the photoelectric image pick-up device; analysis means for analyzing a forming state of the coagulation spot of which the image data is taken by the video image processing means as compared with a desired forming state of a coagulation spot to be produced by irradiation of the treatment laser beam under the irradiation condition set with the input section, the analysis means being connected with the video image processing means; and control means for instructing a change in the irradiation condition as needed based on a result of analysis by the analysis means, the control means being connected with the analysis means.